This invention relates to a system for adhesively mounting panel liners, such as water deflectors or water shields used within automotive vehicle door and body panels and the like types of panel liners.
It is conventional to use a water shield or water deflector panel liner within the doors of automotive vehicles to deflect water which enters the door cavity from seeping through the interior door trim and into the vehicle's interior surfaces. In general, an automotive vehicle door comprises a pair of metal panels which form an exterior and an interior door surface that are joined together along their edges and provide a cavity within which the door window may be lowered. The cavity may also contain window lowering and raising equipment, door locks, sound speakers and the like. Conventionally, the interior door surface is covered with a trim panel formed of cloth-like or plastic trim material, which may be backed with a rigid or semi-rigid trim panel.
In a typical door construction, water may enter the cavity through the opening through which the door window slides. Therefore, holes are formed in the bottom of the door cavity for draining the water from the door cavity. However, when water enters the door cavity, the water may run down along the interior surface of the door panel towards the drain holes but, unless something is done to deflect the water, it may seep into and through the trim panel. The water can stain or deteriorate the trim panel. To protect the trim panel, it is common to position a panel liner, usually formed of a treated paper or thin plastic film or foam sheet material, over the interior surface of the door and beneath the interior door trim panel. That panel liner functions to deflect the water entering the cavity so that the water runs down the liner to the bottom of the door without contacting the trim panel.
Sometimes the liner may be made of a lamination of one or more thin, film-like plastic sheets, adhered to the surface of a thicker foam plastic sheet or non-woven material sheet. That construction may be used to both deflect water and to reduce the transmission of sound through the door and to absorb sound from within the vehicle.
In the foregoing water shield or water deflector type panel liner, it is conventional to secure the panel liner to the surface of the inner panel of the door by means of pressure sensitive adhesive. The pressure sensitive adhesive is applied upon the panel liner at appropriate locations, including around its peripheral edge. During the assembly of the vehicle door, a workman places the liner in position over the surface of the interior panel of the door. Then he presses the liner towards the door panel surface so that the pressure sensitive adhesive adheres to the door panel and secures the panel liner in place.
It is conventional to provide pre-cut panel liner sheets, stackable one upon another for removal, one by one, for use when needed. Alternatively, the liner sheets may be provided in the form of rolls of a number of sheets joined end-to-end. When the sheets are furnished in rolls, a workman simply tears off each successive piece from the roll and applies it to the door.
Examples of panel liners are disclosed in U.S. Pat. No. 4,469,732 issued Sep. 4, 1984 to Isaksen et al for a "Method of Manufacturing Water Deflector for Vehicle Doors"; U.S. Pat. No. 4,604,302 issued Aug. 5, 1986 to Isaksen et al for a "Method of Manufacturing Water Deflector for Vehicle Doors"; U.S. Pat. No. 4,696,848 issued Sep. 29, 1987 to Jones et al for a "Surface Protector With Expansible Pocket"; and U.S. Pat. No. 4,798,130 issued Jan. 17, 1989 to Dixon for a "Door Water Deflector and a Vent." U.S. Pat. Nos. 4,469,732; 4,588,627; and 4,604,302 each illustrate a flexible plastic panel liner having pressure sensitive adhesive applied along the edge of the liner for adhesion to the door panel. The liners are formed in long strips arranged in rolls.
Another example of a similar type of liner or a cover sheet, which is similar to such a liner, is illustrated in U.S. Pat. No. 4,420,520 issued Dec. 13, 1983 to Jones et al for a "Area Coated Paint Mask and Method." This patent illustrates pre-cut cover sheets provided with pressure sensitive adhesive material applied along the peripheral edges of the sheets. The sheets are arranged in stacks.
An example of a panel cover or liner formed of a relatively thick foam plastic sheet, having a pressure sensitive adhesive material for adhering the sheet to supporting panels, for protection against damage, is disclosed in U.S. Pat. No. 4,313,987 issued Feb. 2, 1982 to McCormick for a "Poly-styrene Vehicle Body Protector System." Further, U.S. Pat. No. 3,160,549 issued Dec. 8, 1964 to Caldwell, et al for "Vibration Damping Structures" illustrates a lamination of thicker and thinner sheets, with pressure sensitive adhesive, for application upon supporting structures for sound absorption. Other examples of this general type of liner, which are formed of thin sheet material and are applied upon supporting panel surfaces by means of pressure sensitive adhesives, are known in the art.
Since pressure sensitive adhesive is commonly used for securing such panel liners to the supporting panel or substrate, it is necessary to protect the adhesive before it is adhered to the supporting panel. Particularly, it is necessary to prevent the adhesive on one sheet from sticking to the adjacent surface of the next sheet in either a stack or a roll. Hence, cover sheets or release paper may be used to cover the exposed surfaces of the adhesive until the time that the liner is to be applied to the supporting panel. Where such release paper is used, it is necessary for a workman to remove that paper before pressing the liner against the supporting panel. The paper may be in the form of a large sheet covering the entire liner or in the form of discrete strips covering only the adhesive. Alternatively, the entire liner sheet may be treated on one of its surfaces so that each liner acts as a large release paper or cover for the next liner.
Because panel surfaces or substrates, upon which the panel liners are applied, typically are not perfectly flat, but rather are relatively wavey or have relatively rough surfaces resulting from the manufacturing processes, it is desirable to use a thick deposit of adhesive so that the adhesive fills in the unevenness and, therefore, may accommodate to the underlying substrate surface. This avoids wrinkling or puckering of the liner or the failure of full surface-to-surface contact between the adhesive and the substrate. Protecting the exposed surface of a thick deposit of adhesive raises the problem of preventing the thick deposit of adhesive from flattening or spreading due to contact with adjacent liner sheets in a stack or a roll.
While the liner described herein is particularly useful for automotive door panel liners, the same adhesive related problems exists in lining other vehicle body portions where a liner-like sheet of one sort or another is required to cover a body panel. That is, problems arising out of the use of thick deposits of a pressure sensitive adhesive arranged upon stacked sheets may occur in other types of liners besides door liners.
The present invention is directed towards providing a system for protecting the adhesive deposit located upon panel liner sheets from flattening or spreading before application of the liner upon a support panel or substrate. The system may also include a way of eliminating the need for separable adhesive surface cover sheets or the need to form release surfaces on adjacent sheets.